Contact member for electric switches



June 10, 1930. JANSSQN 1,763,356

CONTACT MEMBER FOR ELECTRIC SWITCHES Filed Dec. 11, 1924 Inven7o2a Patented June 10, 1930 UNITED STATES PATENT OFFICE GUSTAV JANSSON, OF WOLLASTON, MASSACHUSETTS, ASSIGNOB, BY MESNE ASSIGN- MENTS, TO COND'IT ELECTRICAL MANUFACTURING CORPORATION, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS CONTACT MEMBER FOR ELECTRIC SWITCHES Application filed December 11, 1924. Serial No. 755,311.

i; great extent of contact surface, whereby to reduce thewear on the contact members.

A further object is to provide an improved form of contact member.

A yet further object is generally to improve the construction and operation of electric switches.

Fig. 1 is a sectional view of the relatively separable contact members of an oil immersed electric switch embodying the invention.

Fig. 2 is a view of the contact members in a separated position thereof.

Fig. 3 is a plan view of the movable contact member.

As here shown, the stationary contact member 10 immersed in a bath of oil or other arc-quenchingfluid is supported at the lower end of an insulator 12 and connected electrically to the switch terminal 14 through the interposed conducting block 16. Said contact member is more or less hollow and may be formed with an internal screwthread 18 at its upper end for detachable electrical and mechanical connectionwith the external screw-thread of said block 16. Said stationary contact member is approximately internally cylindrical in the upper or bowl portion 19 thereof and may be formed or provided with an annular contracted portion, or throat, 20 intermediate its ends, into which throat the upper cylindrical portion gradually merges. The contact member is provided with a downwardly and outwardly flaring portion, or nozzle, 22 below said throat, which flaring portion forms an arcing surface about which the circuit-interrupting arc is forced to travel, whereby to distribute the wear over a relatively large extent of cold metal; and the cold metal asat said primary contact member and thence pass to the tubular contact member.

The movable contact member 28 is carried at the upper end of a switch rod 29. Said movable contact member is adapted to be moved into and out of said stationary tubular contact member and to have its upper end 30 normally in contact with the primary contact member 24. Said movable contact member has such dimensions that it can move in and out of said tubular contact member and be free from contact therewith. Preferably said movable contact member is more or less barrel-shaped or has an enlarged middle portion 32 which is adapted to be disposed in close proximity, although not in direct contact, with the throat 20 of said tubular con tact member, when the switch is closed and the contact members are in the relative position illustrated in Fig. 1.

WVhen the contact members are separated under load, the circuit-interrupting arc is first drawn between the primary contact member 24 and the upper end of the movable contact member. As said latter contact member continues to move downwardly the arc passes from said primary contact member to some part of the inner surface of said tubular contact member,by reason of the change in effective distance between the separable contact members, due to the shapes thereof, and also due to the expulsion effect on the are by reason of the increased fluid pressure within said bowl, due to the volatilization of the oil within said tubular contact member.

As the movable contact member passes out of the tubular contact member, the arc passes from the throat 20 to the nozzle 22 of said tubular contact member and also from the enlarged middle portion 32 of the movable contact member to the upper end thereof, and, at some instant, may occupy the relative position illustrated in Fig. 2, wherein a indicates the are.

As thus arranged, the arc is caused to travel over a substantial extent of cold metal surfaces which assists in reducing the duration of the arc and provides increased life of the contact members. The expulsion effect of the tubular contact member may be exerted in the direction of the arrow 6 and may serve to distend the arc and thereby to assist in rupturing it.

Hydraulic means are also provided to rotate the are about the contact members whereby to increase the extent of cold surface in contact with the are, thereby further to reduce the duration of the arc and increase the life of the contact members and also to present fresh masses of cold oil to the action of the arc, whereby to assist in quenching it rapidly.

Said hydraulic means includes an impeller 34 fixed to the lower end of said movable contact member 28. Said impeller is provided ith vanes 36 which extend beyond the movable contact member. Said vanes are suitably curved or shaped to act upon the body of oil through which the impeller is moved, as the contact members are separated, and impart a swirling motion to the body of oil surrounding the movable contact member, as indicated by the arrow 0. Said swirling oil current acts upon the arc and tends to rotat it about and in contact with the flaring lower end of the tubular contact member 10, and also about the movable contact member, thereby to distribute the action of the are over a relatively large area of the cold contacts and sweep away the gases and vapors generated from the oil and surrounding the arc and present fresh and cold masses of oil to the are whereby to assist materially in quenching it.

The construction may be otherwise modified without departing from the spirit of the invention.

1 claim:

1. A contact member for an electric switch comprising a. tubular electrically conducting and arc-supporting body provided in ternally with a primary contact member in the upper end and spaced from the side walls of and connected electrically with said tubular body, said tubular body having a reduced arcing throat disposed below said primary contact member, and a downwardly and outwardly divergent electrically conducting portion communicating with said throat and contituting an arcing face for said contact member, the inner face of said tubular body between said primary contact member and said throat also constituting an arcing face over which the circuit interrupting arc is adapted to travel.

2. A contact member for an electric switch comprising a tubular electrically conducting and arc-supporting body open only at its lower end and provided internally with a pri- :nary contact member at the upper end and spaced from the side walls thereof, said tubular body converging to a reduced arcing throat intermediate its ends and diverging outwardly and downwardly from said throat to a terminal arc face at its lower and open end, the inner face of said tubular body between said primary contact member and said throat also constituting an arcing face over which the circuit interrupting arc is adapted to travel.

3. Contact members for an electric switch comprising a stationary tubular electrieall i conducting and arc-supporting body each at its lower end and provided internally with a primary contact member at its upper end and spaced from the side walls thereof, said. tubular body having a reduced throat intermediate its length and a lower downwardly and outwardly divergent electrically conducting portion extended from said throat and terminated in an arcing face the inner face of said tubular body between said primary cont: ct member and said throat also constituting an arcing face over which the circuit interrupting arc is adapted to travel, and a movable contact member arranged. to move into and out of said tubular bOC y in proximity to its inner arcing face and free from contact therewith and into and out of contact with said primary contact member.

4-. Contact members for an electric switch comprising a stationary tubular conducting and arc-supporting body open at its lower end and provided internally with a primary contact member at its upper end and spaced from the side walls thereof, said tubular body having a continuous inner arcing face including a reduced throat intermediate its length and a lower downwardly and outwardly divergent portion extended from said throat, which portion constitutes an arc-supporting terminal, and a movable-contact memberv arranged to move into and out of said tubular body in proximity to said arcing face and free from contact therewith and into and out of contact with said primary contact member, said movable contact member comprising an approximately cylindrical member having an enlarged intermediate portion arranged to be disposed in the throat of said tubular body when the switch is closed.

Contact members for an electric switch comprising a stationary tubular conducting body open at its lower end and provided internally with a primary contact member at its upper end and spaced from the side walls thereof, said tubular body having a reduced throat intermediate its length and a lower downwardly and outwardly divergent portion extended from said throat, and a movable-contact member arranged to move into and out of said tubular body free from con tact therewith and into and out of contactwith said primary contact member, said movable con act member comprising an approximately cylindrical member having an enlarged intermediate portion and reduced upper and lower portions, said enlarged intermediate portion arranged to be disposed in the throat of said tubular body when the switch is closed.

6. A contact member for an electric switch comprising a tubular electrically conducting body having internally an enlarged bowl, a

reduced throat, and an expanding nozzle all arranged in communication in the order named, and a primary contact member disposed in the bowl in line with said throat, the expanded end of said nozzle constituting an arcing face for said contact member, the inner face of said tubular body between said primary contact member and said throat also constituting an arcing face over which the circuit interrupting arc is adapted to travel.

7. Contact members for an electric switch including a fixed contact member comprising a tubular electrically conducting body having internally an enlarged bowl, a reduced throat, and an expanding nozzle provided with a terminal arcing face, all arranged in communication in the order named, the inner face of said tubular body also constituting an arcing face over which the circuit interrupting arc is adapted to travel, a primary contact member disposed in the bowl in line with said throat, and a movable contact member comprising an approximately cylindrical body constructed and arranged to enter said nozzle and throat and make contact with said primary contact member.

8. A movable contact member for an electric switch having in combination therewith fiuid-guiding means to impart a rotary movement to the fluid surrounding it about the contact member as a center, whereby to rotate the are about the contactmember.

9. A movable contact member for an electric switch having in combination therewith fluid-guiding means to impart a rotary movement to the fluid surrounding it about the contact member as a center and by the movement of said contact member, whereby to rotate the are about said contact member.

10. A movable contact member for an electric switch comprising an approximately cylindrical body having an upper arcing portion, and fluid-guiding means disposed below said arcing portion arranged to impart a rotary movement to the fluid surrounding the upper arcing portion of said body about an axis approximately coincident with the axis of said body and by the movement of said contact member, whereby to rotate the are about said upper arcing-portion.

11. A movable contact member for an electric switch comprising an approximately cylindrical body movable approximately in line with its axis and having a contact face on its upper portion, and an impeller fixed to a lower portion of said body and having laterally-extended vanes shaped to impart a rotary movement to the fluid surrounding said cylindrical body and its contact face by the movement of said contactmember, whereby to rotate the are about said upper portion.

12. In an electric switch, relatively separable contact members about which the circuit-interrupting arc is free to rotate repeatedly, and hydraulic means to rotate the circuit-interrupting are around said contact members.

13. In an electric switch, relatively separable contact members about which the circuit-interrupting arc is free to rotate repeatedly, and hydraulic means to rotate the circuit-interrupting are about said contact members including means to rotate the fluid surrounding the arc about the axis including said contact members.

14. In an electric switch, relatively separable contact members about which the circuit-interrupting arc is free to rotate repeatedly, and hydraulic means to rotate the circuit-interrupting are about said contact members including means actuated by the movement of the movable contact member to rotate the fluid surrounding the are about the axis including said contact members.

15. In an electric switch, a stationary contact member having an annular arcing face, a movable contact member arranged for cir cuit-interrupting movement approximately along the axis of said annular arcing face, and hydraulic means to impart a rotational movement of the circuit-interrupting are about said annular arcing face.

16. In an electric switch, a stationary contact member having an annular arcing face, a movable contact member arranged for circuit-interrupting movement approximately along the axis of said annular arcing face, and hydraulic means actuated by movement of the movable contact member arranged to impart a rotational movement of the circuitinterrupting are about said annular arcing face.

17. An, arcing member for an electric switch having an annular-arcing face and hydraulic means carried by said member to rotate the circuit-interrupting are around said annular arcing face.

I 18. In an electric switch, a stationary contact member having an annular arcing face, a co-operating contact member movable approximately along the axis of said annular arcing face, and means carried by said movable contact member arranged to rotate the fluid surrounding the contact members approximately about the axis of said annular arcing face.

19. In an electric switch, a stationary contact member comprising a tubular body having a lower annular arcing face, a movable contact member movable into and out of said tubular body, and hydraulic means to rotate the circuit-interrupting arc about said annular arcing face and movable contact member.

20. In an electric switch, a stationary contact member comprising a tubular body having a lower annular arcing face, a movable contact member marable into and out of said tubular body, and having a contact face at its upper end, and an annular impeller axially disposed on said movable contact member below its contact face arranged to rotate the fluid surrounding the contact members approximately about the axes of said contact members.

21. In an electric switch, a stationary contact member comprising a tubular body hav ing a lower annular arcing face, a movable contact member movable into and out of said tubular body, and ha ing a contact face at its upper end, and an impeller disposed on said movable contact member below its contact face, and having vanes arranged to impart a rotary movement to the fluid surrounding said contact members approximately about the axis of said contact members.

22. In an electric switch. cooperating separable contact members, at least one of which has an annular arcing face, and hydraulic means including an impeller having blades arranged to effect relatire rotary movement between the arc and said annular arcing face.

In an electric switch, a pair of relatively separable contact members, and hydraulic means including an impeller having blades arranged to rotate the circuit--interrupting arc in a continuous path around the axes of said contact members.

In testimony whereof, have signed my name to this specification.

GUSTAV JANSSON. 

